Oncogenic human papillomaviruses in extra-genital Bowen disease revealed by in situ hybridization

Background. The association between mucosal oncogenic human papillomaviruse s (HPV) and bowenoid papulosis or genital Bowen's disease is well documente d. In contrast this association with extra-genital Bowen's disease is poorl y studied. The aim of this study was to detect oncogenic (16/18, 31/33/51) and non oncogenic (8/11) mucosal HPV using a in situ hybridization method i n 28 skin biopsy specimens of extra-genital Bowen's disease. Patients and methods. Twenty-eight cases of extra-genital Bowen's disease s een in the period 1990-96 in the Dermatology department were included: 19 w omen and 9 men (mean age: 72 years). Bowen's disease locations were: hands and feet (8 cases), limbs (11 cases), face (8 cases), trunk (1 case). Blind ed histopathologic examination confirmed the diagnosis of Bowen's disease a nd signs of HPV infection (koilocytosis). In situ hybridization was perform ed using three biotinylated probes detecting HPV types 6/11, 16/18, 31/33/5 1. Results. Oncogenic HPV genoma was detected in 8 skin samples (28.6 p. 100). In all these cases, 16/18 probe was positive and in two cases, both 16/18 and 31/33/51 probes were positive; 4/8 Bowen's diseases of the extremities were positive for HPV. Koilocytes were found in 6/8 of skin samples with po sitive HPV detection. Discussion. Mucosal oncogenic HPV are detected by in situ hybridization in 28.6 p. 100 of extra-genital Bowen's disease. In situ hybridization is an e asier technique than Southern-Blot hybridization which is the gold standard . Five studies reported similar results and three studies reported differen t results that we discuss. A precise understanding of oncogenic HPV implica tion in the development of extra-genital Bowen's disease could lead to the development of new therapeutic strategies (topical cidofovir or imiquimod).